Microbacterium sulfonylureivorans sp. nov., isolated from sulfonylurea herbicides degrading consortium

A novel Gram-stain positive, aerobic, motile, rod-shaped bacterium, designated strain LAM7116^T was isolated from a sulfonylurea herbicides degrading consortium enriched with birch forest soil from Xinjiang. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain LAM7116^T was closely related to the members of the genus Microbacterium, with the highest similarity to Microbacterium flavescens DSM 20643^T (98.48%) and Microbacterium kitamiense Kitami C2^T (98.48%). Strain LAM7116^T formed a distinct subclade with M. flavescens DSM 20643^T within the genus Microbacterium in the 16S rRNA gene phylogenetic trees. The genomic DNA G + C content of LAM7116^T was 69.9 mol%. The digital DNA-DNA hybridization (dDDH) value between strain LAM7116^T and M. flavescens DSM 20643^T was 27.20%. The average nucleotide identity (ANI) value was 83.96% by comparing the draft genome sequences of strain LAM7116^T and M. flavescens DSM 20643^T. The major fatty acids were anteiso-C_15:0, anteiso-C_17:0, iso-C_17:0, and iso-C_16:0. The respiratory menaquinones of strain LAM7116^T were MK-13 and MK-14. The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol, an unidentified lipid, and an unidentified glycolipid. The peptidoglycan contained the amino acids glycine, lysine, alanine, and glutamic acid. Based on the phenotypic characteristics and genotypic analyses, we consider that strain LAM7116^T represents a novel species, for which the name Microbacterium sulfonylureivorans sp. nov. was proposed. The type strain is LAM7116^T (= CGMCC 1.16620^T = JCM 32823^T). Strain LAM7116^T secreted auxin IAA and grew well in Ashby nitrogen-free culture medium. Genomic results showed that strain LAM7116^T carried the nitrogenase iron protein (nifU and nifR3) gene, which indicated that strain LAM7116^T has the potential to fix nitrogen and promote plant growth. At same time, strain LAM7116^T can degrade nicosulfuron (a kind of sulfonylurea herbicides) using glucose as carbon source. Microbacterium sulfonylureivorans sp. nov. LAM7116^T is a potential candidate for the biofertilizers of organic agriculture areas, and may possess potential to be used in bioremediation of nicosulfuron-contaminated environments.